This invention relates to a process for preparing ortho-(alkylthio)phenols by reacting certain phenols with dialkyl disulfides in the presence of zirconium phenoxide catalysts.
The compounds resulting from the process of the invention are useful as intermediates for the preparation of certain sulfonylurea herbicides.
U.S. Pat. No. 4,324,920 discloses a process for the preparation of ortho-(alkylthio)phenols by contacting phenols with dialkyl disulfides in the presence of catalytic amounts of aluminum phenoxide.
U.S. Pat. No. 2,923,743 discloses a process for the preparation of aryl-alkyl thioethers from aromatic compounds (such as xylene, phenol, 4-chlorophenol) and dialkyl disulfides, in the presence of a catalyst such as aluminum chloride, ferric chloride or bleaching earth (e.g., Tonsil.RTM.).
None of the above disclosures involve the process of the present invention. None of the above disclosures involve the catalyst of the invention.